This invention relates to a suspension system and particularly to a compact suspension system incorporating an air spring and an air lift spring self contained within a hanger.
The invention incorporates a highly compact group of components that includes a self contained air lift spring. A hanger that depends downwardly from the chassis side rail supports an eccentric bolt and bushing assembly to which a torque rod and axle seat assembly is journalled. The torque rod and axle seat assembly includes an axle seat that is connected underslung to an axle that is a trailing or pusher axle. An air spring is mounted between the axle seat and a bracket that is connected to the side rail. The torque rod and axle seat are connected together by two bushing assemblies to create an overall flexing beam.
A special movable wall is made integral with and projects upwardly from the torque beam so that it revolves about the eccentric bolt and bushing assembly as the torque beam swings with up and down movements of the axle. The movable wall revolves relative to a stationary wall that is supported by the hanger. The hanger is further specially formed to provide a large pocket in the area between the movable wall and the stationary wall to accommodate the mounting of a lift air spring between those two walls.
To further conserve space as required for the compact suspension system of this invention, the lift air spring is mounted on a generally horizontal axis made possible because the stationary plate is substantially vertical and the movable plate projects generally upwardly at an angle to the substantially vertical fixed plate.
The axle load spring has an internal bumper that limits the upward movement of the axle caused by operating forces. The air lift spring has an internal bumper that limits the downward movement of the axle caused by downward operating forces. When inflated, the air lift spring lifts the axle, such as is desired when the vehicle is not loaded.